Gas burning fireplaces operate based on a supply of gas introduced to the firebox in the fireplace. The gas is ignited to produce a fire. The possibility exists that ignition may not occur until there is substantial build up of gas in the firebox in which case there is a resultant explosion. Gas operated fireplaces are therefore provided with pressure relief openings covered by some type of a pressure relief valve otherwise known as an explosion dampener. An explosion dampener will normally seal the pressure relief opening from the firebox and is designed to automatically open and then close in the event of an explosion.
There are different types of explosion dampeners presently available on gas burning fireplaces. However, many of the in-use explosion dampeners are subject to failure because they warp with heat of the firebox and as a result of the warpage, will not over time provide an effective seal at the pressure relief opening. This creates a dangerous situation in that fumes created within the firebox are then allowed to leak into the surrounding room air.
In addition, most currently available explosion dampeners are quite expensive in design and add substantially to the cost of the fireplace.